The Optical Society
From Lectures to Explosives Detection: Green Laser Pointer Identifies Traces of Dangerous Chemicals in Real-Time
Schematic drawing of the Raman spectrometer, including a laser pointer, dichroic mirror, prism, objective, x,y motorized translational stage, long wavepass edge filter, lens and a detector (spectrometer/intensified charge-coupled device). Image courtesy Ilana Bar, Ben Gurion University of the Negev.
WASHINGTON, Oct. 9, 2012—By using an ordinary green laser pointer, the kind commonly found in offices and college lecture halls, an Israeli research team has developed a new and highly portable Raman spectrometer that can detect extremely minute traces of hazardous chemicals in real time. The new sensor’s compact design makes it an excellent candidate for rapid field deployment to disaster zones and areas with security concerns. The researchers will present their findings at Laser Science XXVIII—the American Physical Society Division of Laser Science’s Annual Meeting—collocated with the Optical Society’s (OSA) Annual Meeting, Frontier in Optics (FiO), taking place in Rochester, N.Y. next week.
Raman spectrometers rely on highly focused beams of light at precise wavelengths to illuminate small samples of materials. Very sensitive detectors then study the spectra of light that has been re-emitted, or scattered, by the sample. Most of this scattered light retains its original frequency or color, but a very small percentage of that light is shifted ever so slightly to higher or lower wavelengths, depending on the unique vibrational modes of the sample being studied. By comparing the shifted and the original wavelengths, it’s possible to determine the precise chemicals present in the sample.
The researchers brought this capability down to size by constructing their Raman spectrometer using a low-power and low-cost commercial green laser pointer. The green laser’s relatively short wavelength helped to improve the detection of the inherently weak Raman signal. The spectrometer also has the capability to first scan the entire sample optically, sweeping from side to side, to locate individual particles of interest – a task usually performed by large and cumbersome Raman microscopes.
“Since the overall system is modular, compact, and can be readily made portable, it can be easily applied to the detection of different compounds and for forensic examination of objects that are contaminated with drugs, explosives, and particularly explosive residues on latent fingerprints,” said Ilana Bar, a researcher with the Department of Physics at Ben-Gurion University of the Negev in Israel. “With proper investment this system could be deployed quite quickly as a consumer product.” Other members of the research team include Itamar Malka, Alona Petrushansky, and Salman Rosenwaks.
Presentation LTh3I.3, “Detection of Explosives and Latent Fingerprint Residues Utilizing Laser Pointer Based Raman Spectroscopy,” takes place Thursday, Oct. 18 at 2:30 p.m. EDT at the Rochester Riverside Convention Center in Rochester, N.Y.
EDITOR’S NOTE: An image showing a schematic of the system is available to members of the media upon request. Contact Angela Stark, firstname.lastname@example.org.
PRESS REGISTRATION: A press room for credentialed press and analysts will be located in the Rochester Riverside Convention Center, Sunday through Thursday, Oct. 14-18. Those interested in obtaining a press badge for FiO should contact OSA's Angela Stark at 202.416.1443 or email@example.com. A full list of meeting highlights for press is available on the FiO website.
About the Meeting
Frontiers in Optics (FiO) 2012 is the Optical Society’s (OSA) 96th Annual Meeting and is being held together with Laser Science XXVIII, the annual meeting of the American Physical Society (APS) Division of Laser Science (DLS). The two meetings unite the OSA and APS communities for five days of quality, cutting-edge presentations, fascinating invited speakers and a variety of special events spanning a broad range of topics in optics and photonics—the science of light—across the disciplines of physics, biology and chemistry. FiO 2012 will also offer a number of Short Courses designed to increase participants’ knowledge of a specific subject in the optical sciences while offering the experience of insightful teachers. An exhibit floor featuring leading optics companies will further enhance the meeting. More information at www.FrontiersinOptics.org.
Uniting more than 180,000 professionals from 175 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics. For more information, visit www.osa.org.